Varāha-avatāra: Viṣṇu’s subterranean intervention and the cosmic nāda (Śānti-parva 202)
यद् व्याप्यभूद् व्यापकं साधकं च यन्मन्त्रवत् स्थास्यति चापि लोके | यः सर्वहेतु:ः परमात्मकारी तत् कारणं कार्यमतो यदन्यत्,श्रुतिके कथनानुसार जो व्यापक, व्याप्प और उनका साधन है, जो सम्पूर्ण लोकमें सदा ही स्थित रहनेवाला कूटस्थ, सबका कारण और स्वयं ही सब कुछ करनेवाला है, वही परम कारण है। उसके सिवा जो कुछ है, सब कार्यमात्र है
yad vyāpyabhūd vyāpakaṃ sādhakaṃ ca yanmantravat sthāsyati cāpi loke | yaḥ sarvahetuḥ paramātmakārī tat kāraṇaṃ kāryam ato yad anyat ||
Bhishma explains that the supreme principle is that which pervades all and is itself all-pervading, which also serves as the means by which things are accomplished, and which—like a sacred mantra—abides steadily in the world. It is the universal cause and the inner Self that brings all about. That alone is the ultimate cause; whatever exists apart from it is merely an effect, dependent and secondary.
भीष्म उवाच
The verse distinguishes the ultimate cause (kāraṇa)—the all-pervading Paramātman that is both immanent and transcendent—from all other things, which are merely effects (kārya) and thus dependent. It emphasizes a single supreme ground that pervades, sustains, and accomplishes everything.
In the Śānti Parva’s instruction section, Bhīṣma is teaching Yudhiṣṭhira about the highest reality and the basis of dharma. Here he frames a metaphysical hierarchy: the Supreme Self as the universal cause, and the world of phenomena as its effects.